Magnetic Characterization of Direct-Write Free-Form Building Blocks for Artificial Magnetic 3D Lattices
Magnetic Characterization of Direct-Write Free-Form Building Blocks for Artificial Magnetic 3D Lattices
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DOI：
10.3390/ma11020289
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发表时间：
2018-02-01
期刊：
影响因子：
3.4
通讯作者：
Huth, Michael
中科院分区：
文献类型：
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作者：
Al Mamoori, Mohanad K. I.;Keller, Lukas;Huth, Michael
三维（3D）纳米磁性，其中自旋配置延伸到衬底平面的垂直方向，允许更复杂的，分层系统和新颖的磁效应的设计。作为实现这一目标的重要一步，我们最近展示了通过聚焦电子束诱导沉积的纳米树和纳米立方体结构的铁磁CoFe的独立铁磁3D纳米结构的直写制造。在这里，我们提出了一个全面的表征这些结构的磁性能的本地杂散场测量使用高分辨率的微霍尔磁强计。在宽范围的温度和不同角度的外部施加的磁场相对于传感器的表面平面的测量支持相应的微磁模拟，这部分相当复杂的磁化配置的整体切换行为解释得非常好。特别是，模拟产生的矫顽和切换字段是在良好的定量对应关系与所测量的矫顽和切换字段假设体金属含量为100原子%的bcc Co3Fe组成。我们表明，热不稳定的磁化状态可以重复准备和他们的寿命控制的意愿，实现动态和热活性的磁性配置的先决条件，如果积木要用于晶格结构。
Three-dimensional (3D) nanomagnetism, where spin configurations extend into the vertical direction of a substrate plane allow for more complex, hierarchical systems and the design of novel magnetic effects. As an important step towards this goal, we have recently demonstrated the direct-write fabrication of freestanding ferromagnetic 3D nano-architectures of ferromagnetic CoFe in shapes of nano-tree and nano-cube structures by means of focused electron beam induced deposition. Here, we present a comprehensive characterization of the magnetic properties of these structures by local stray-field measurements using a high-resolution micro-Hall magnetometer. Measurements in a wide range of temperatures and different angles of the externally applied magnetic field with respect to the surface plane of the sensor are supported by corresponding micromagnetic simulations, which explain the overall switching behavior of in part rather complex magnetization configurations remarkably well. In particular, the simulations yield coercive and switching fields that are in good quantitative correspondence with the measured coercive and switching fields assuming a bulk metal content of 100 at % consisting of bcc Co3Fe. We show that thermally-unstable magnetization states can be repetitively prepared and their lifetime controlled at will, a prerequisite to realizing dynamic and thermally-active magnetic configurations if the building blocks are to be used in lattice structures.